An electrostatic discharge circuit

Abstract

An electrostatic discharge circuit includes at least an electrostatic discharge zener diode, an NMOS transistor, and a PMOS transistor. The electrostatic discharge zener diode is used for lowering the breakdown voltage and making the electrical current discharge through it, thereby preventing the circuit device from burning out and greatly enhancing the function of electrostatic discharge protection.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application is based on, and claims priority from, Taiwan Application Serial Number 94128101, filed Aug. 17, 2005, the disclosure of which is hereby incorporated by reference herein in its entirety. BACKGROUND OF THE INVENTION [0002] 1. Field of Invention [0003] The invention relates to an electrostatic discharge (ESD) circuit and, in particular, to an ESD circuit using the ESD zener diode. [0004] 2. Related Art [0005] In daily life, separating different materials from or rubbing different materials against each other can produce static electricity. For example, squeezing, cutting, moving, churning, and filtering in production processes; and walking, standing, and taking off clothes in daily life all produce static electricity. One therefore may say that static electricity is everywhere. Even our bodies and surroundings may carry a lot of electrostatic voltage, up to thousands or even tens of thousands of volts. Such static ...

AI Technical Summary

Benefits of technology

[0013] Another objective of the invention is to provide an ESD zener diode which can be used in an ESD circuit to lower its breakdown voltage, thus providing better ESD protection.

[0014] According to a preferred embodiment of the invention, the ESD circuit includes an NMOS transistor, a PMOS transistor, and an ESD zener diode. The ESD zener diode is used to decrease the breakdown voltage, so that the electrical current discharges through it, thereby preventing the circuit from burning out and also greatly enhancing the function of ESD protection.

Problems solved by technology

Such static electricity may not have great influence on human bodies, but it may cause damage to some devices that are sensitive to electrostatic effects so that they partially or totally lose their normal functions.

However, there is a very serious problem with these ESD circuits.

That is, the breakdown voltages of these ESD circuits are about 8-10 V. In other words, they cannot provide any protection for circuits operating below 8 V.

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